This section of the book is from the "Stories of Animal Sagacity" book, by William Henry Giles Kingston.
Dogs and horses frequently form friendships. A Newfoundland dog had attached himself to a mare belonging to his master, and seemed to consider himself especially the guardian of his less sagacious companion. Whenever the groom began to saddle the mare, the dog used to lie down with his nose between his paws, watching the proceeding. The moment the operation was finished, up jumped the dog, seized the reins in his mouth, and led the mare to her master, following him in his ride.
On returning home, the reins being again given to him, he would lead his friend back to the stable. If, on his arrival, the groom happened to be out of the way, he would bark vehemently till he made his appearance, and then hand over his charge to him.
You may be young and little, but if you exercise discretion and judgment, you may assist those much bigger and older than yourself. Learn from the dog, however, not to give yourself airs in consequence; you will have simply performed your duty in making yourself useful.